Figures & data
Figure 1 Climatic characteristics of the experimental site during the study period. (a) Temperature, (b) evaporation and (c) rainfall.
Table 1 Initial physical and chemical properties of the soil
Table 2 Nitrogen applied in the different treatments in the first 2 years (2002 and 2003)
Table 3 Characteristics of the poultry litter (PL) used in the experiment (data corrected to dry weight)
Table 4 Crop husbandry information
Figure 2 Mean dry matter yields for the four growing seasons. (a) The first and second years when both the poultry litter (PL) and mineral fertilizers were applied and (b) the third and fourth years when no fertilizer was used. Error bars represent the standard error (n = 4). Letters above the bars indicate significant differences among treatments within a year. T1, control; T2, mineral fertilizer at the low rate; T3, mineral fertilizer at the high rate; T4, T5 and T6, poultry manure at the low, medium and high rates, respectively.
Table 5 Nitrogen uptake, residual N effect and apparent nitrogen recovery efficiency (ANRE)
Figure 3 Nitrogen, P2O5 and K2O accumulation over the first 3 years of the experiment. Error bars represent the standard error (n = 4). T1, control; T2, mineral fertilizer at the low rate; T3, mineral fertilizer at the high rate; T4, T5 and T6, poultry manure at the low, medium and high rates, respectively.
Figure 4 Soil NO3-N concentration at the time of soil sample collection (end of the third growing season) at 0–20, 20–40 and 40–60 cm depths. T1, control; T2, mineral fertilizer at the low rate; T3, mineral fertilizer at the high rate; T4, T5 and T6, poultry manure at the low, medium and high rates, respectively.
